Hydraulic valve pilot control module and control method

Abstract

A hydraulic valve pilot control module relates to the technical field of hydraulic control. In an existing valve body space, through the structural design of the valve sleeve and the ejector rod, the design concept that the through-flow area is increased and an inner hole of the valve sleeve is enlarged at present is abandoned. The ejector rod is of a T-shaped structure, the ejector rod and the steel ball are arranged in the valve sleeve, when the unloading valve port is opened, the unloading valve port is not limited by the diameter of the ejector rod any more and is directly communicated with the oil outlet from the oil inlet, and the through-flow area is increased. The unloading speed is accelerated, and the operation efficiency of a hydraulic system is improved. When the valve port is not opened, the pressure of the pilot oil is not changed at the beginning, the upward thrust on the steel ball is not changed, and the upward hydraulic pressure borne by the steel ball is maximum at the moment; during unloading, only the coil I needs to be electrified, downward force acting on the steel ball can be reduced, the valve port is instantly opened, pilot oil is unloaded, the condition that unloading cannot be achieved is avoided along with the gradual opening of the valve port and the gradual reduction of hydraulic force, the fault tolerance of the machining size of parts is increased, the production cost is reduced, and meanwhile the performance of a hydraulic system is more stable.

Description

Technical Field

[0001] The present invention relates to a hydraulic control system, and in particular to a hydraulic valve pilot control module and a control method. Background Art

[0002] The load-sensing multi-way valve (LSMV) is a core control element in hydraulic systems, achieving on-demand flow and pressure distribution through a pressure feedback mechanism. Its core function is to provide real-time feedback of the load pressure of actuators (such as hydraulic cylinders and motors) to the variable displacement mechanism of the pump, ensuring that the pump's output pressure is always slightly higher than the maximum load pressure (typically maintaining a pressure differential of 1.5-2.5 MPa). Simultaneously, the flow control valve precisely distributes flow to each branch, creating a dual closed-loop "pressure-flow" control system.

[0003] The pilot control module of the load-sensing multi-way valve is a core component in the hydraulic system for remote operation, signal amplification, and precise control. It drives the main valve core through the pilot pressure signal (usually 2-5MPa), converting the small operating force into a large flow of hydraulic energy output. In the normally closed function opening and closing structure of the pilot control module, such as Figure 4-5 As shown, the oil circuit in the valve sleeve is controlled by a steel ball and a push rod. The long step of the push rod passes through the hole of the guide sleeve. The guide sleeve and the valve sleeve have an interference fit. The steel ball can move up and down in the valve sleeve, and at the same time push the push rod to move up and down in the valve sleeve.

[0004] Under normal conditions, the push rod has no downward thrust. When oil flows into the oil inlet, the pressure generated by the hydraulic oil pushes the steel ball to drive the push rod upward. The steel ball blocks the φ1.3 hole inside the valve sleeve, cutting off the passage between the pilot oil inlet and outlet. The pilot oil circuit is pressurized. Figure 4 When the push rod has a downward thrust, the push rod pushes the steel ball to overcome the upward force of the hydraulic oil on the steel ball, the steel ball moves downward, the valve port opens, and the hydraulic oil flows through Figure 5 The middle dotted line path is from the pilot oil inlet to the oil outlet. The oil outlet is connected to the atmosphere, and the pilot oil circuit is unloaded.

[0005] In the pilot oil circuit, the overall size is made small. In this normally closed structure, the internal push rod size is also small, which is not only difficult to process but also inconvenient to install. Secondly, when the unloading valve port is opened, the shaft area at the lower end of the push rod is located in the φ1.3 hole of the valve sleeve, which reduces the flow area (the annular area between φ1.3 and φ0.8), and the flow area is also subject to the gap between the steel ball and the inner hole of the valve sleeve. The smaller the gap, the smaller the flow area and the slower the unloading. If you want to increase the flow area, you need to increase the inner hole of the valve sleeve and the φ1.3 hole, but the increase in the inner hole of the valve sleeve will lead to slow pressure buildup. After the φ1.3 hole is increased, the contact range with the steel ball increases. From the pressure formula F=PS (F is force, P is pressure, S is area), it can be seen that when the hydraulic oil pressure remains unchanged, the area increases and the force value increases accordingly, resulting in an increase in the force value required to be output by the electromagnet. The increase in the electromagnet force value either increases the current, which will increase heat generation, or increases the number of coil turns, which will increase the volume of the electromagnet.

[0006] In addition, when unloading, the hydraulic oil pressure is the largest at the beginning (needs 40N and above), and as the path opens, the hydraulic oil pressure gradually decreases. Therefore, during the unloading process, the thrust required must be large at the beginning, such as Figure 7 As shown, Figure 7 The force-displacement curve of the push rod is shown in the figure. The ordinate represents the output force of the push rod, and the abscissa represents the displacement of the push rod. When the pressure is applied, the steel ball and the push rod are at the bottom. At this time, the upper end face of the push rod is 0.7 mm away from the iron core. Because the upper end face of the push rod fits the lower end face of the push rod, the lower end face of the push rod is 0.7 mm away from the lower end face of the iron core. At this time, the thrust of the electromagnet must be greater than or equal to 40 N. As can be seen from the figure, when the displacement is between 0.1-0.6 mm, that is, the distance from the lower end face of the push rod to the lower end face of the iron core is 0.6-1.1 mm, the force value must be ≥40 N to meet the demand. This requires relatively high machining accuracy for the valve sleeve, guide sleeve and push rod. If the cumulative error is too large, the output force of the electromagnet will be insufficient, less than the hydraulic oil pressure, resulting in the valve port not being able to open and unload.

[0007] Therefore, how to increase the flow area and improve the operating efficiency and stability of the hydraulic system within a limited space is a technical problem that needs to be solved urgently in this case. Summary of the Invention

[0008] In response to the above problems, the present invention provides a hydraulic valve pilot control module and control method that reduces production costs, increases flow area, and improves the operating efficiency and stability of the hydraulic system within the original space.

[0009] The technical solution of the present invention is: Hydraulic valve pilot control module, including: The housing is sealed and fixedly connected to the valve body; the bottom of the valve body is provided with an oil inlet connected to the control chamber; an iron core, fixedly disposed in the housing and sealed to the valve body; A guide sleeve, which is fixedly mounted on the iron core and spaced apart from the iron core; An armature assembly is slidably disposed in the guide sleeve, with an end portion extending from the iron core and into the valve body; A permanent magnet, a fixed sleeve is arranged on the guide sleeve; A coil is fixedly sleeved on the outside of the permanent magnet; The valve sleeve is arranged in the control cavity of the valve body and is provided with a flow channel running vertically. A ball cavity is provided in the flow channel, and a plurality of through holes are provided on the side of the ball cavity to facilitate unloading of hydraulic oil to the oil outlet. A guide sleeve, fixedly arranged on the top of the valve sleeve control chamber; The top rod has a T-shaped cross section and is slidably arranged in the guide sleeve. The top end is connected to the armature assembly, and the bottom end extends into the ball cavity and is connected to the steel ball.

[0010] Specifically, the armature assembly includes: An armature is slidably disposed in the guide sleeve and is located on the side of the iron core; A push rod has one end fixedly connected to the armature and the other end extending into the guide sleeve.

[0011] Specifically, a distance is provided between the valve sleeve and the control chamber, and the valve sleeve and the control chamber are sealed by a sealing ring.

[0012] Specifically, the diameter of the flow channel is smaller than the diameter of the spherical cavity.

[0013] Specifically, a groove is provided on the top of the guide sleeve.

[0014] Specifically, the cross section of the groove is trapezoidal.

[0015] Specifically, the top of the iron core is a plane.

[0016] Specifically, the bottom of the armature is a plane.

[0017] Specifically, the permanent magnet and the coil have the same height.

[0018] A control method for a hydraulic valve pilot control module includes: Under normal conditions, when the coil is not energized, it does not generate a magnetic field and exerts no force on the armature assembly. The iron core is magnetized by the magnetic field generated by the permanent magnet and, under the action of the electromagnetic force, exerts a force on the armature assembly, pushing the ejector rod toward the steel ball. The ejector rod pushes the steel ball against the bottom of the valve sleeve ball cavity, cutting off the passage between the oil inlet and outlet, and pressurizing the pilot oil circuit. When the coil is energized, the magnetic field generated by the coil is in opposite directions to the magnetic field generated by the permanent magnet and has equal strength. The magnetic fields cancel each other out and no force is applied to the armature assembly. The armature assembly does not move and no force is applied to the ejector rod. When oil flows into the oil inlet, the pressure generated by the hydraulic oil pushes the steel ball to drive the ejector rod to move upward. The channel between the oil inlet and the oil outlet opens, and the pilot oil flows from the oil inlet to the oil outlet. The oil outlet is connected to the atmosphere, and the pilot oil circuit is unloaded.

[0019] The present invention abandons the current design concept of increasing the flow area by enlarging the inner hole of the valve sleeve through the structural design of the valve sleeve and the push rod within the existing valve body space. The push rod adopts a T-shaped structure and is placed in the valve sleeve with the steel ball. When the unloading valve port is opened, it is no longer restricted by the diameter of the push rod and directly connects the oil inlet to the oil outlet, and the flow area becomes larger; the unloading speed is accelerated, and the operating efficiency of the hydraulic system is improved. When the valve port is not opened, the pilot oil pressure remains unchanged at the beginning, and the upward thrust on the steel ball remains unchanged. At this time, the upward liquid pressure on the steel ball is the largest; when unloading, as long as the coil is energized, the downward force acting on the steel ball will become smaller, the valve port will open instantly, and the pilot oil will be unloaded. As the valve port gradually opens, the liquid pressure gradually decreases, and the unloading problem will not occur. The fault tolerance of the processing size of the parts is increased, which not only reduces the production cost, but also makes the performance of the hydraulic system more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the coil of the present invention when it is powered off; Figure 2 yes Figure 1 Schematic diagram of the structure of the mid-spherical cavity; Figure 3 This is a schematic diagram of the structure of the coil of the present invention when it is energized; Figure 4 This is a schematic diagram of the state of the push rod in the prior art; Figure 5 This is a schematic diagram of the structure of the ejector pin in the prior art in state 2; Figure 6 It is a structural diagram of the existing technology push rod; Figure 7 is the force-displacement curve of the push rod; In the figure, 1 is the housing, 2 is the guide sleeve, 3 is the coil, 4 is the armature, 5 is the push rod, 6 is the iron core, 7 is the guide sleeve, 8 is the push rod, 9 is the steel ball, 10 is the valve sleeve, 11 is the valve body, 12 is the permanent magnet, and 13 is the oil outlet. DETAILED DESCRIPTION

[0021] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0022] In the description of the present invention, it should be understood that terms such as "upper," "lower," "left," "right," "vertical," and "horizontal" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are used solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0023] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0024] Hydraulic valve pilot control module, including: The housing 1 is detachably and sealedly fixedly connected to the valve body 11; the bottom of the valve body 11 is provided with an oil inlet connected to the control chamber; The iron core 6 is fixedly arranged in the housing 1 by interference fit and is sealed with the valve body 11; the top of the iron core 6 is flat; The guide sleeve 2 is fixedly mounted on the step of the iron core 6 and is spaced apart from the iron core 6 by a plurality of sealing rings; In this case, a groove is provided on the top of the guide sleeve 2, and the cross section of the groove is trapezoidal.

[0025] An armature assembly is slidably disposed in the guide sleeve 2, with its end extending from the iron core 6 and into the valve body 11; The permanent magnet 12 is fixedly sleeved on the guide sleeve 2; The coil 3 is fixedly sleeved on the outside of the permanent magnet 12 ; the permanent magnet 12 and the coil 3 are at the same height.

[0026] The valve sleeve 10 is arranged in the control cavity of the valve body 11 and is provided with a flow channel running through from top to bottom. A ball cavity 101 is provided in the flow channel. A plurality of through holes 102 are provided on the side of the ball cavity 101 to unload the hydraulic oil to the oil outlet. The diameter of the flow channel is smaller than the diameter of the ball cavity 101.

[0027] A distance is provided between the valve sleeve 10 and the control chamber, and the valve sleeve 10 is sealed by a sealing ring.

[0028] The guide sleeve 7 is fixedly arranged on the top of the control chamber of the valve sleeve 10; The push rod 8 has a T-shaped cross section and is slidably disposed within the guide sleeve 7. Its top end is connected to the armature assembly, and its bottom extends into the ball cavity 101 and is connected to the steel ball 9. The push rod 8 extends into the ball cavity 101 from the top opening of the valve sleeve 10. The steel ball 9 can move up and down within the valve sleeve 10, and the range of movement of the steel ball 9 is limited by the downward pressure of the push rod 8.

[0029] The armature assembly includes: The armature 4 is slidably disposed in the guide sleeve 2 and is located on the side of the iron core 6; the bottom of the armature 4 is flat; One end of the push rod 5 is fixedly connected to the armature 4, and the other end extends into the guide sleeve 7.

[0030] A control method for a hydraulic valve pilot control module includes: Under normal circumstances, such as Figure 1 As shown, when the coil 3 is not energized, the coil 3 does not generate a magnetic field and has no force on the armature assembly; the iron core 6 is magnetized by the magnetic field generated by the permanent magnet 12 and is acted upon by the electromagnetic force F, which generates a downward force F on the armature assembly, thereby pushing the push rod 8 toward the steel ball 9. The push rod 8 pushes the steel ball 9 against the bottom of the ball cavity 101 of the valve sleeve 10, cutting off the channel between the oil inlet and the oil outlet 11. The pilot oil circuit starts to be pressurized, and the pressure gradually increases from 0 to pressure p. The pressure exerts an upward force Fp on the steel ball, and Fp≤F (armature thrust). Once Fp>F, the steel ball valve port opens, relieving excess pressure until Fp=F, thereby providing overload protection for the oil circuit. When coil 3 is energized (the direction of the energized current is the same as Figure 1 The coil current direction of the structure is opposite), the magnetic field generated by the coil 3 and the magnetic field generated by the permanent magnet 12 are opposite in direction and equal in strength. The magnetic fields cancel each other out and no force is generated on the armature assembly. F=0, the armature assembly does not move, and there is no force on the push rod 8. When oil is fed into the oil inlet, the pressure Fp generated by the hydraulic oil pushes the steel ball 9 and the push rod 8 to move upward together. The channel between the oil inlet and the oil outlet 11 is opened, and the pilot oil flows from the oil inlet to the oil outlet 11. The oil outlet 11 is connected to the atmosphere, and the pilot oil circuit is unloaded. Figure 3 shown.

[0031] The T-shaped design of the ejector pin 8 in this case reduces machining complexity and facilitates installation. When the unloading valve port is opened, it is no longer restricted by the diameter of the ejector pin 8, allowing the oil inlet to flow directly to the outlet, increasing the flow area. This speeds up unloading and improves the operating efficiency of the hydraulic system. Furthermore, the tolerance for machining part dimensions is increased, which not only reduces production costs but also makes the hydraulic system more stable.

[0032] When the valve port is not opened, the pilot oil pressure remains unchanged at the beginning, and the upward thrust on the steel ball 9 remains unchanged. At this time, the upward liquid pressure on the steel ball is the largest; when unloading, as long as the coil is energized, the downward force acting on the steel ball 9 will become smaller, the valve port will open instantly, and the pilot oil will be unloaded. As the valve port gradually opens, the liquid pressure gradually decreases, and the situation of being unable to unload will not occur.

[0033] When the oil circuit needs to be pressurized, it switches from the unloading state to the pressurizing state. During this process, the valve port is gradually closed, and the force of the hydraulic oil on the steel ball gradually increases from small to large; the coil is de-energized, and the armature assembly moves downward under the action of the magnetic field. Since the upper end surface of the iron core and the lower end surface of the armature are both flat, the air gap is uniform, and the output force increases sharply as the air gap decreases. The output force trend of the armature assembly is a process from small to large, which is consistent with the change in the force of the hydraulic oil on the steel ball, and there will be no problem of failure to pressurize or delayed pressure initiation.

[0034] Regarding the content disclosed in this case, the following points need to be explained: (1) The drawings of the embodiments disclosed in this case only involve the structures involved in the embodiments disclosed in this case. Other structures can refer to the general design; (2) In the absence of conflict, the embodiments and features of the embodiments disclosed in this case may be combined with each other to form new embodiments; The above are only specific implementation methods disclosed in this case, but the protection scope of the present disclosure is not limited thereto. The protection scope disclosed in this case should be based on the protection scope of the claims.

Claims

1. Hydraulic valve pilot control module, characterized in that: include: The housing (1) is sealed and fixedly connected to the valve body (11); the bottom of the valve body (11) is provided with an oil inlet connected to the control chamber; An iron core (6) is fixedly disposed in the housing (1) and is sealedly connected to the valve body (11); A guide sleeve (2) is fixedly mounted on the iron core (6) and spaced apart from the iron core (6); An armature assembly is slidably disposed in the guide sleeve (2), with an end portion extending from the iron core (6) and extending into the valve body (11); A permanent magnet (12) is fixedly sleeved on the guide sleeve (2); A coil (3) is fixedly sleeved on the outside of the permanent magnet (12); A valve sleeve (10) is arranged in the control cavity of the valve body (11), and is provided with a flow passage that passes through from top to bottom. A ball cavity (101) is provided in the flow passage, and a plurality of through holes (102) are provided on the side of the ball cavity (101) to facilitate unloading of hydraulic oil to the oil outlet. A guide sleeve (7) is fixedly arranged on the top of the control chamber of the valve sleeve (10); The top rod (8) has a T-shaped cross section and is slidably disposed in the guide sleeve (7). The top end is connected to the armature assembly, and the bottom end extends into the ball cavity (101) and is connected to the steel ball (9).

2. The hydraulic valve pilot control module according to claim 1, characterized in that: The armature assembly comprises: An armature (4) is slidably arranged in the guide sleeve (2) and is located on the side of the iron core (6); A push rod (5) has one end fixedly connected to the armature (4) and the other end extending into the guide sleeve (7).

3. The hydraulic valve pilot control module according to claim 1, characterized in that: A distance is provided between the valve sleeve (10) and the control chamber, and the valve sleeve (10) and the control chamber are sealed by a sealing ring.

4. The hydraulic valve pilot control module according to claim 1, characterized in that: The diameter of the flow channel is smaller than the diameter of the spherical cavity (101).

5. The hydraulic valve pilot control module according to claim 1, characterized in that: The top of the guide sleeve (2) is provided with a groove.

6. The hydraulic valve pilot control module according to claim 5, characterized in that: The cross section of the groove is trapezoidal.

7. The hydraulic valve pilot control module according to claim 1, characterized in that: The top of the iron core (6) is a plane.

8. The hydraulic valve pilot control module according to claim 7, characterized in that: The bottom of the armature (4) is a plane.

9. The hydraulic valve pilot control module according to claim 1, characterized in that: The permanent magnet (12) and the coil (3) are at the same height.

10. A control method for a hydraulic valve pilot control module, comprising the hydraulic valve pilot control module according to claim 1, characterized in that: Under normal conditions, the coil (3) is not energized, so the coil (3) does not generate a magnetic field and has no force on the armature assembly; the iron core (6) is magnetized by the magnetic field generated by the permanent magnet (12), and is acted upon by the electromagnetic force, generating a force on the armature assembly, pushing the push rod (8) toward the steel ball (9), and the push rod (8) pushes the steel ball (9) against the bottom of the ball cavity (101) of the valve sleeve (10), cutting off the passage between the oil inlet and the oil outlet (11), and causing the pilot oil circuit to be pressurized; When the coil (3) is energized, the magnetic field generated by the coil (3) and the magnetic field generated by the permanent magnet (12) are in opposite directions and have equal strengths. The magnetic fields cancel each other out, and no force is generated on the armature assembly. The armature assembly does not move, and no force is generated on the push rod (8). When oil is fed into the oil inlet, the pressure generated by the hydraulic oil pushes the steel ball (9) and drives the push rod (8) to move upward. The channel between the oil inlet and the oil outlet (11) is opened, and the pilot oil flows from the oil inlet to the oil outlet (11). The oil outlet (11) is connected to the atmosphere, and the pilot oil circuit is unloaded.

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